+++ /dev/null
-######################## BEGIN LICENSE BLOCK ########################
-# The Original Code is Mozilla Communicator client code.
-#
-# The Initial Developer of the Original Code is
-# Netscape Communications Corporation.
-# Portions created by the Initial Developer are Copyright (C) 1998
-# the Initial Developer. All Rights Reserved.
-#
-# Contributor(s):
-# Mark Pilgrim - port to Python
-#
-# This library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or (at your option) any later version.
-#
-# This library is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-# Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public
-# License along with this library; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
-# 02110-1301 USA
-######################### END LICENSE BLOCK #########################
-
-from typing import Tuple, Union
-
-from .big5freq import (
- BIG5_CHAR_TO_FREQ_ORDER,
- BIG5_TABLE_SIZE,
- BIG5_TYPICAL_DISTRIBUTION_RATIO,
-)
-from .euckrfreq import (
- EUCKR_CHAR_TO_FREQ_ORDER,
- EUCKR_TABLE_SIZE,
- EUCKR_TYPICAL_DISTRIBUTION_RATIO,
-)
-from .euctwfreq import (
- EUCTW_CHAR_TO_FREQ_ORDER,
- EUCTW_TABLE_SIZE,
- EUCTW_TYPICAL_DISTRIBUTION_RATIO,
-)
-from .gb2312freq import (
- GB2312_CHAR_TO_FREQ_ORDER,
- GB2312_TABLE_SIZE,
- GB2312_TYPICAL_DISTRIBUTION_RATIO,
-)
-from .jisfreq import (
- JIS_CHAR_TO_FREQ_ORDER,
- JIS_TABLE_SIZE,
- JIS_TYPICAL_DISTRIBUTION_RATIO,
-)
-from .johabfreq import JOHAB_TO_EUCKR_ORDER_TABLE
-
-
-class CharDistributionAnalysis:
- ENOUGH_DATA_THRESHOLD = 1024
- SURE_YES = 0.99
- SURE_NO = 0.01
- MINIMUM_DATA_THRESHOLD = 3
-
- def __init__(self) -> None:
- # Mapping table to get frequency order from char order (get from
- # GetOrder())
- self._char_to_freq_order: Tuple[int, ...] = tuple()
- self._table_size = 0 # Size of above table
- # This is a constant value which varies from language to language,
- # used in calculating confidence. See
- # http://www.mozilla.org/projects/intl/UniversalCharsetDetection.html
- # for further detail.
- self.typical_distribution_ratio = 0.0
- self._done = False
- self._total_chars = 0
- self._freq_chars = 0
- self.reset()
-
- def reset(self) -> None:
- """reset analyser, clear any state"""
- # If this flag is set to True, detection is done and conclusion has
- # been made
- self._done = False
- self._total_chars = 0 # Total characters encountered
- # The number of characters whose frequency order is less than 512
- self._freq_chars = 0
-
- def feed(self, char: Union[bytes, bytearray], char_len: int) -> None:
- """feed a character with known length"""
- if char_len == 2:
- # we only care about 2-bytes character in our distribution analysis
- order = self.get_order(char)
- else:
- order = -1
- if order >= 0:
- self._total_chars += 1
- # order is valid
- if order < self._table_size:
- if 512 > self._char_to_freq_order[order]:
- self._freq_chars += 1
-
- def get_confidence(self) -> float:
- """return confidence based on existing data"""
- # if we didn't receive any character in our consideration range,
- # return negative answer
- if self._total_chars <= 0 or self._freq_chars <= self.MINIMUM_DATA_THRESHOLD:
- return self.SURE_NO
-
- if self._total_chars != self._freq_chars:
- r = self._freq_chars / (
- (self._total_chars - self._freq_chars) * self.typical_distribution_ratio
- )
- if r < self.SURE_YES:
- return r
-
- # normalize confidence (we don't want to be 100% sure)
- return self.SURE_YES
-
- def got_enough_data(self) -> bool:
- # It is not necessary to receive all data to draw conclusion.
- # For charset detection, certain amount of data is enough
- return self._total_chars > self.ENOUGH_DATA_THRESHOLD
-
- def get_order(self, _: Union[bytes, bytearray]) -> int:
- # We do not handle characters based on the original encoding string,
- # but convert this encoding string to a number, here called order.
- # This allows multiple encodings of a language to share one frequency
- # table.
- return -1
-
-
-class EUCTWDistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = EUCTW_CHAR_TO_FREQ_ORDER
- self._table_size = EUCTW_TABLE_SIZE
- self.typical_distribution_ratio = EUCTW_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- # for euc-TW encoding, we are interested
- # first byte range: 0xc4 -- 0xfe
- # second byte range: 0xa1 -- 0xfe
- # no validation needed here. State machine has done that
- first_char = byte_str[0]
- if first_char >= 0xC4:
- return 94 * (first_char - 0xC4) + byte_str[1] - 0xA1
- return -1
-
-
-class EUCKRDistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = EUCKR_CHAR_TO_FREQ_ORDER
- self._table_size = EUCKR_TABLE_SIZE
- self.typical_distribution_ratio = EUCKR_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- # for euc-KR encoding, we are interested
- # first byte range: 0xb0 -- 0xfe
- # second byte range: 0xa1 -- 0xfe
- # no validation needed here. State machine has done that
- first_char = byte_str[0]
- if first_char >= 0xB0:
- return 94 * (first_char - 0xB0) + byte_str[1] - 0xA1
- return -1
-
-
-class JOHABDistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = EUCKR_CHAR_TO_FREQ_ORDER
- self._table_size = EUCKR_TABLE_SIZE
- self.typical_distribution_ratio = EUCKR_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- first_char = byte_str[0]
- if 0x88 <= first_char < 0xD4:
- code = first_char * 256 + byte_str[1]
- return JOHAB_TO_EUCKR_ORDER_TABLE.get(code, -1)
- return -1
-
-
-class GB2312DistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = GB2312_CHAR_TO_FREQ_ORDER
- self._table_size = GB2312_TABLE_SIZE
- self.typical_distribution_ratio = GB2312_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- # for GB2312 encoding, we are interested
- # first byte range: 0xb0 -- 0xfe
- # second byte range: 0xa1 -- 0xfe
- # no validation needed here. State machine has done that
- first_char, second_char = byte_str[0], byte_str[1]
- if (first_char >= 0xB0) and (second_char >= 0xA1):
- return 94 * (first_char - 0xB0) + second_char - 0xA1
- return -1
-
-
-class Big5DistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = BIG5_CHAR_TO_FREQ_ORDER
- self._table_size = BIG5_TABLE_SIZE
- self.typical_distribution_ratio = BIG5_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- # for big5 encoding, we are interested
- # first byte range: 0xa4 -- 0xfe
- # second byte range: 0x40 -- 0x7e , 0xa1 -- 0xfe
- # no validation needed here. State machine has done that
- first_char, second_char = byte_str[0], byte_str[1]
- if first_char >= 0xA4:
- if second_char >= 0xA1:
- return 157 * (first_char - 0xA4) + second_char - 0xA1 + 63
- return 157 * (first_char - 0xA4) + second_char - 0x40
- return -1
-
-
-class SJISDistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = JIS_CHAR_TO_FREQ_ORDER
- self._table_size = JIS_TABLE_SIZE
- self.typical_distribution_ratio = JIS_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- # for sjis encoding, we are interested
- # first byte range: 0x81 -- 0x9f , 0xe0 -- 0xfe
- # second byte range: 0x40 -- 0x7e, 0x81 -- oxfe
- # no validation needed here. State machine has done that
- first_char, second_char = byte_str[0], byte_str[1]
- if 0x81 <= first_char <= 0x9F:
- order = 188 * (first_char - 0x81)
- elif 0xE0 <= first_char <= 0xEF:
- order = 188 * (first_char - 0xE0 + 31)
- else:
- return -1
- order = order + second_char - 0x40
- if second_char > 0x7F:
- order = -1
- return order
-
-
-class EUCJPDistributionAnalysis(CharDistributionAnalysis):
- def __init__(self) -> None:
- super().__init__()
- self._char_to_freq_order = JIS_CHAR_TO_FREQ_ORDER
- self._table_size = JIS_TABLE_SIZE
- self.typical_distribution_ratio = JIS_TYPICAL_DISTRIBUTION_RATIO
-
- def get_order(self, byte_str: Union[bytes, bytearray]) -> int:
- # for euc-JP encoding, we are interested
- # first byte range: 0xa0 -- 0xfe
- # second byte range: 0xa1 -- 0xfe
- # no validation needed here. State machine has done that
- char = byte_str[0]
- if char >= 0xA0:
- return 94 * (char - 0xA1) + byte_str[1] - 0xA1
- return -1
projects / dlqueue.git / blobdiff